JPH0991662A - Magnetic recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a magnetic recording medium excellent in electromagnetic transducing characteristics, running performance, durability and corrosion resistance by forming a metallic magnetic film having a prescribed compsn. on one side of a substrate and forming a diamond-like carbon film and a fluorine- contg. lubricant film on the magnetic film. SOLUTION: A metallic magnetic film 2 of Fe-C-O having 1,800Åthickness is formed by an oblique vapor deposition means on the front side of a PET film 1 having 7μm thickness. The magnetic film 2 has a compsn. consisting of 75at.% Fe, 15at.% C and 10at.% O. A diamondlike carbon film 3 having 75Å thickness is formed on the magnetic film 2 and a metallic back coating film 4 of a Cu-Al alloy having 2,000Å thickness is formed on the rear of the PET film 1. Fluorine-contg. lubricant films each having 20Å thickness are then formed by ultrasonic spraying on the films 3, 4. The objective magnetic recording medium fit for high density recording is obtd. using low-cost Fe and this medium is excellent in electromagnetic transducing characteristics, running performance, durability and corrosion resistance.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a magnetic recording medium having an Fe-based metal magnetic film.

[0002]

A metal thin film type magnetic recording medium in which a magnetic film is formed by dry plating means such as vapor deposition or sputtering is widely known. There are various materials for forming the magnetic film. For example, Co-Ni and Co-Cr magnetic alloys have been mainly used so far.

However, Co, Ni, Cr, etc. are expensive. In view of this problem, Fe is drawing attention. That is, Fe is low in price and rarely causes pollution problems. However, when Fe is used,
The examination of how the entire structure should be made is in the process of development, and it is a groping condition.

Accordingly, an object of the present invention is to provide a metal thin film type magnetic recording medium which, when Fe is used as a material, is excellent in electromagnetic conversion characteristics, rich in durability and corrosion resistance, and excellent in running stability. Is to provide.

[0005]

The object of the present invention is to provide a support and Fe, C and O provided on one surface of the support.
A Fe-C-O-based metal magnetic film having one or more layers, a diamond-like carbon film provided on the Fe-C-O-based metal magnetic film, and a diamond-like carbon film provided on the diamond-like carbon film. And a fluorine-based lubricant film formed on the magnetic recording medium.

Further, the support and one or more Fe layers having Fe, C and O provided on one surface side of the support.
-C-O-based metal magnetic film, diamond-like carbon film provided on the Fe-C-O-based metal magnetic film, and fluorine-based lubricant film provided on the diamond-like carbon film And a metal thin film type back coat film provided on the other surface side of the support.

Further, the support and one or more layers of Fe having Fe, C and O provided on one surface side of the support.
-C-O-based metal magnetic film, diamond-like carbon film provided on the Fe-C-O-based metal magnetic film, and fluorine-based lubricant film provided on the diamond-like carbon film A magnetic recording medium comprising a metal thin film type back coat film provided on the other surface side of the support, and a fluorine-based lubricant film provided on the back coat film. To be achieved.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises a support, and one or more Fe—C—O-based metal magnetic films having Fe, C and O provided on one surface of the support, and Fe-C-
It comprises a diamond-like carbon film provided on the O-based metal magnetic film, and a fluorine-based lubricant film provided on the diamond-like carbon film.

In particular, a support and one or more layers of F having Fe, C and O provided on one surface side of the support.
an e-C-O-based metal magnetic film, a diamond-like carbon film provided on the Fe-C-O-based metal magnetic film,
A film of a fluorine-based lubricant provided on the diamond-like carbon film, and a metal thin film type back coat film provided on the other surface of the support,
On a support, one or more Fe—C—O-based metal magnetic films having Fe, C and O provided on one surface of the support, and the Fe—C—O-based metal magnetic film A diamond-like carbon film provided on the diamond-like carbon film, and a fluorine-based lubricant film provided on the diamond-like carbon film,
It comprises a metal thin film type back coat film provided on the other surface side of the support, and a fluorine-based lubricant film provided on the back coat film.

A magnetic film other than the Fe—C—O based metal magnetic film may be provided between the Fe—C—O based metal magnetic film and the support. The support of the magnetic recording medium of the present invention may be magnetic or non-magnetic. As typical ones, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate,
Polycyclohexylene dimethylene terephthalate, polyesters such as polyethylene bisphenoxycarboxylate, polyolefins such as polyethylene and polypropylene, cellulose derivatives such as cellulose acetate butyrate and cellulose acetate propionate, vinyl such as polyvinyl chloride and polyvinylidene chloride Examples include non-magnetic plastic materials such as system resins, polyamide, and polycarbonate. Of course, it is not limited to these. Also, various kinds of processing may be performed. For example,
Surface treatment is performed by corona discharge or other appropriate means. Further, polyester, polyurethane, oligomer or the like may be applied for improving the adhesiveness.

On one side of this support, PV such as oblique deposition is formed.
Fe-by the D (physical vapor deposition) method
One or two or more layers of C—O based metal magnetic film are provided. This film formation will be described below by taking an evaporation method having a high film formation rate as an example. First, the inside of the oblique vapor deposition apparatus is evacuated to a predetermined vacuum degree, the Fe-based metal material is evaporated by an electron gun or other means, and the Fe-based metal particles are attached and deposited on the running support. At the time of this attachment / deposition, the Fe-based metal vaporized particles or the deposition surface is irradiated with carbon ions or oxygen ions (or oxygen gas) to form a magnetic film of 800 to 5000 Å thickness provided on the non-magnetic support. A Fe—C—O based metal magnetic film is used. In addition, F
e: C: O is 50 to 90 at. % (Atomic%): 5 to 35
at. %: 5-35 at. % Is preferred. More preferably, Fe: C: O is 60 to 86 at. %: 7 to 25a
t. %: 7 to 25 at. %. Since the content of the metal elements other than Fe is small, for example, 5 wt% or less, the variation due to these metal elements is small, and is defined only by Fe, C, and O.

A protective film is provided on the surface of the magnetic film. As a material for forming this protective film, for example, Al, S
Although oxides, nitrides, carbides, boron nitrides, etc. of metals such as i, Ti, Cr, Zr, Nb, Mo, Ta, W, etc. are considered, diamond-like carbon was selected in the present invention. The diamond-like carbon protective film has a thickness of about 10 to 500Å. Particularly, about 30 to 200Å is preferable.

The protective film made of diamond-like carbon is formed by using, for example, CVD means. That is, the CVD device is operated on the support (metal magnetic film) running from the supply-side roll arranged in the vacuum tank to the winding-side roll through the cooling-can roll, and is attached to the cooling-can roll. When a hydrocarbon gas plasma is blown onto the formed metal magnetic film, a diamond-like carbon film is formed on the surface. As the hydrocarbon-based gas for forming the diamond-like carbon film, a paraffin-based hydrocarbon such as methane, an aromatic hydrocarbon such as benzene, or nitrogen containing N such as a homologue or derivative thereof as a ring constituent element is used. Examples of the contained cyclic hydrocarbons. In addition, H ₂ , O ₂ , N ₂ , NH ₃ , NO ₂ , NO
Etc. can also be used together with a hydrocarbon gas.

On the other surface (back surface) of the support, a back coat layer, particularly a metal thin film type back coat film (metal film) is provided. That is, for example, a wet-type plating means such as electroless plating, a vapor deposition method, a DC sputtering method, an AC sputtering method, a high-frequency sputtering method, a DC magnetron sputtering method, a high-frequency magnetron sputtering method, an ion beam sputtering method, etc. Is provided. The back coat film has a thickness of 1000 to 5000.
Å, more preferably about 1500 to 3500Å.
As the material of the metal particles forming the back coat film, for example, metals such as Al, Zn, Sn, Ni, Ag, Fe and Ti are used. Also, Cu-Al-X (where X is M
One or more selected from the group consisting of n, Fe and Ni) based alloys, Al-Si based alloys, Ti alloys and the like are used. Cu-Al-X (where X is Mn, Fe,
One or two or more selected from the group of Ni) -based alloy has a Cu content of 70 to 90 at%, an Al content of 8 to 25 at%, and a Mn content of 0.5 to 4 at%.
It is preferable that the Fe content is 0.4 to 5 at%, the Ni content is 0.4 to 4 at%, and the total content of Mn, Fe, and Ni is 1 to 6 at%. Also, Al-Si
The Al content in the system alloy is preferably 15 to 70 at%, and the Si content is preferably 15 to 70 at%.

Further, at the time of forming the back coat film, an oxidizing gas, oxygen ions or oxygen radical may be supplied to oxidize the surface layer portion of the metal film. Alternatively, a highly reactive nitrogen compound, nitrogen ion, or nitrogen radical may be supplied to nitride the surface layer portion of the metal-based film. Alternatively, a highly reactive carbon compound, carbon ion or carbon radical may be supplied to carbonize the surface layer portion of the metal-based film. It is preferable to supply a highly reactive carbon compound, carbon ion, or carbon radical to carbonize the surface layer portion of the metal-based film because it resembles the diamond-like carbon film.

The metal thin film type magnetic film or the metal thin film type back coat film may be formed by forming the magnetic film and then forming the back coat film. Conversely, the magnetic film may be formed after forming the back coat film. Alternatively, the films may be formed in almost the same process. Incidentally, in terms of process, since the diamond-like carbon film is provided on the magnetic film, it is preferable to form the magnetic film after forming the back coat film.

After the Fe--C--O type metal magnetic film, the diamond-like carbon film, and the metal thin film type back coat film are formed as described above, the fluorine type lubricant film is immersed or ultrasonically sprayed. 20-70Å by means such as
It is provided with a certain thickness. This fluorine-based lubricant is applied on the diamond-like carbon film. Alternatively, it is applied on the diamond-like carbon film and the metal thin film type back coat film. Of course, it is preferable to attach it on both sides. As the lubricant, for example, - (C (R) F- CF 2 -O) p - ( where group such as R is _{F, CF 3, CH 3)} , in particular HOOC-CF ₂
(OC ₂ F ₄ ) _p (OCF ₂ ) _q -OCF ₂ -COOH, F- (CF ₂ CF ₂ CF ₂ O) _n -CF
₂ CF ₂ COOH Carboxyl group-modified perfluoropolyether such as HOCH ₂ -CF ₂ (OC ₂ F ₄ ) _p (OCF ₂ ) _q -OC
F ₂ -CH ₂ OH, HO- (C ₂ H ₄ -O) _m -CH _2- (OC ₂ F ₄ ) _p (OCF ₂ ) _q-
OCH _2- (OCH ₂ CH ₂ ) _n -OH, F- (CF ₂ CF ₂ CF ₂ O) _n -CF ₂ CF ₂ CH ₂ OH
Alcohol-modified perfluoropolyethers such as those mentioned above, or saturated hydrocarbon groups such as alkyl groups, or unsaturated hydrocarbon groups, or aromatic hydrocarbon groups, or other functional groups on one or part of the molecule. The thing with a base etc. is mentioned. The molecular weight is preferably from 500 to 50,000. More specifically, Montecatini's FOMBLIN
Z DIAC, FOMBLIN Z DOL, and Daikin Industries' Demnum SA are available.

[0018]

Embodiment 1 FIG. 1 shows a magnetic recording medium according to the present invention (8 mm
1 is a schematic view of a first embodiment of a magnetic tape for VTR), FIG. 2 is a metal magnetic film forming apparatus, FIG. 3 is a diamond-like carbon film forming apparatus, and FIG. 4 is a back coat film forming apparatus. In FIG. 1, 1 is a PET film having a thickness of 7 μm.

2, 1800Å-thick Fe—C—O (Fe 75 at.%: C 15 at.) Provided on the surface of the PET film 1 by oblique vapor deposition using the apparatus of FIG.
%: O10 at. %) Based metal magnetic film. 3 is shown in FIG.
It is a diamond-like carbon film having a thickness of 75Å provided on the Fe—C—O-based metal magnetic film 2 by using the above apparatus.

Numeral 4 is 2000 made of Cu-Al alloy provided on the back surface of the PET film 1 by using the apparatus shown in FIG.
Å This is a thick metal film (back coat film). In this metal thin film type magnetic recording medium, first, the PET film 1 is placed in the vapor deposition apparatus of FIG. 4 (in FIG. 4, 1 is a PET film, 11 is a cooling can roll, and 12 is in a crucible (evaporation source). Cu-Al alloy 13, 13 is an electron gun), the Cu-Al alloy 12 filled in the crucible in the apparatus is irradiated with an electron beam, and the PET film 1 is introduced while introducing oxygen gas.
After the Cu-Al alloy particles are vapor-deposited on the back surface of the wafer, the oblique vapor deposition apparatus shown in FIG. Ion gun, 23 is an oxygen ion irradiation ion gun, and 24 is an electron gun), and the Fe-based metal material 21 filled in the crucible in the apparatus is irradiated with an electron beam to emit carbon ions and oxygen ions into the ion guns 22, 23. Fe-based metal particles are vapor-deposited on the surface of the PET film 1 while being irradiated with. Then, the ECR plasma CVD apparatus of FIG.
Among them, 1 is PE on which a Fe—C—O type metallic magnetic film is formed.
A T film, 31 is guided to an ECR plasma CVD apparatus), and a diamond-like carbon film 3 is provided on the Fe—C—O based metal magnetic film 2.

Numerals 5a and 5b are fluorine-based lubricants (FOMBL) having a thickness of 20Å, which are provided by ultrasonic spraying after the diamond-like carbon film 3 and the back coat film 4 are formed.
INZ DIAC) film.

[0022]

[Embodiment 2] In Embodiment 1, the Fe-C-O-based metal magnetic film is formed of Fe-CO (Fe 90 at.%: C5a).
t. %: O 5 at. %) Based metal magnetic film was used, and the same procedure as in Example 1 was performed.

[0023]

Third Embodiment In the first embodiment, the Fe—C—O based metal magnetic film is formed of Fe—C—O (Fe 60 at.%: C 35
at. %: O 5 at. %) Based metal magnetic film was used, and the same procedure as in Example 1 was performed.

[0024]

Fourth Embodiment In the first embodiment, the Fe—C—O based metal magnetic film is formed of Fe—C—O (Fe 65 at.%: C 5a).
t. %: O 30 at. %) Based metal magnetic film was used, and the same procedure as in Example 1 was performed.

[0025]

[Comparative Example 1] Example 1 except that an Fe metal magnetic film was used instead of the Fe-C-O-based metal magnetic film.
It was carried out according to.

[0026]

Comparative Example 2 In Example 1, the carbon ions were not irradiated during the deposition of the Fe-based metal particles, and only the oxygen ions were irradiated.
In place of the Fe—C—O based metal magnetic film, Fe—O (Fe
70 at. %: O 30 at. %) Based metal magnetic film was used, and the same procedure as in Example 1 was performed.

[0027]

COMPARATIVE EXAMPLE 3 The procedure of Example 1 was repeated except that a Si target was used instead of the diamond-like carbon film 3 and a SiO _x film was formed by DC magnetron sputtering while flowing an oxygen gas. .

[0028]

COMPARATIVE EXAMPLE 4 Example 1 was repeated except that myristic acid (lubricant) was used in place of the fluorine-based lubricant.

[0029]

[Characteristics] 7MHz for the magnetic tapes obtained in the above examples
The reproduction output of the luminance signal, running stability, durability, and corrosion resistance were examined, and the results are shown in Table-1. The running stability is based on the measured value of jitter, the durability is based on the result of still durability, and the corrosion resistance is 1 at 60 ° C and 90% RH.
The reduction rate of the saturation magnetic flux density Bs after leaving for a week was used as a guide. The jitter was measured by using a commercially available Hi8mm VTR modified and connected with a jitter meter. Still durability was 7MHz when still reproduction was performed for 5 hours.
The decrease in the output of the luminance signal at was measured using a spectrum analyzer.

Table-1 Reproduction output (dB) Jitter (ns) Still durability (dB) Corrosion resistance ΔBs (%) Example 1 +7.4 47 -0.8 -4 Example 2 +6.9 49 -1. 2-8 Example 3 +7.1 46 -0.3 -2 Example 4 +6.6 45 -0.5 -2 Comparative Example 1 Unmeasurable Unmeasurable -26 Comparative Example 2 -3.8 51 -3 0.5-17 Comparative Example 3 +7.2 55 -2.1-10 Comparative Example 4 +7.0 69 -2.6-12 * The reproduction output is based on a commercially available coating type metal tape (0 dB). A magnetic recording medium which is a combination of a Fe—C—O based metal magnetic film, a diamond-like carbon film provided thereon, and a fluorine-based lubricant film provided on the diamond-like carbon film is In Comparative Examples 1, 2, 3, and 4 in which any one of these constituent requirements is missing It can be seen that it is superior to the magnetic recording medium. That is, it is possible to understand how important the combination of the present invention is.

For example, as can be seen from the comparison between Example 1 and Comparative Examples 1 and 2, a diamond-like carbon film,
Even if the requirements for the fluorine-based lubricant film and the metal thin film type back coat film are satisfied, if the requirements for the Fe—C—O-based metal magnetic film are lacking, electromagnetic conversion characteristics, running properties, durability, and Corrosion resistance is poor, and the features of the present invention cannot be achieved at all.

Further, as can be seen from the comparison between Example 1 and Comparative Example 3, even if the requirements of the Fe—C—O type metal magnetic film, the fluorine type lubricant film and the metal thin film type back coat film are satisfied. However, if the requirements for the diamond-like carbon film are lacking, the durability is poor and the features of the present invention cannot be achieved at all. Further, as can be seen from the comparison between Example 1 and Comparative Example 4, even if the requirements of the Fe—C—O-based metal magnetic film, the diamond-like carbon film, and the metal thin film type back coat film are satisfied, the fluorine-based lubricant is used. If you lack the membrane requirements of
The running property and durability are poor, and the features of the present invention cannot be achieved at all.

[0033]

The magnetic recording medium suitable for high density recording can be obtained by using inexpensive Fe. Moreover, this magnetic recording medium has excellent electromagnetic conversion characteristics, running properties, durability, and corrosion resistance.

[Brief description of drawings]

FIG. 1 is a schematic view of a magnetic recording medium according to the present invention.

FIG. 2 Film forming apparatus for metal magnetic film

[Fig. 3] Diamond-like carbon film forming apparatus

FIG. 4 Film forming apparatus for back coat film

[Explanation of symbols]

 1 Support 2 Metal Magnetic Film 3 Diamond-Like Carbon Film 4 Metal Film (Backcoat Film) 5a, 5b Fluorine Lubricant Film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location C23C 14/56 C23C 14/56 K (72) Inventor Junko Ishikawa Large-scale Akabane, Kai Town, Haga-gun, Tochigi Prefecture 2606 Kao Co., Ltd. Information Science Laboratory (72) Inventor Katsumi Endo, Kaiga-cho, Haga-gun, Tochigi Prefecture 2606 Akabane Kao Co., Ltd. Information Science Laboratory

Claims (3)

[Claims] 1. A support, one or more layers of Fe—C—O-based metal magnetic film having Fe, C, and O provided on one side of the support, and the Fe—C—O system. A magnetic recording medium comprising a diamond-like carbon film provided on a metal magnetic film, and a fluorine-based lubricant film provided on the diamond-like carbon film. 2. A support, one or more Fe—C—O-based metal magnetic film having Fe, C and O provided on one surface of the support, and the Fe—C—O system. A diamond-like carbon film provided on the metal magnetic film, a fluorine-based lubricant film provided on the diamond-like carbon film, and a metal thin film type backing film provided on the other surface side of the support. A magnetic recording medium comprising a coat film. 3. A support, one or more layers of Fe—C—O-based metal magnetic film having Fe, C and O provided on one surface of the support, and the Fe—C—O system. A diamond-like carbon film provided on the metal magnetic film, a fluorine-based lubricant film provided on the diamond-like carbon film, and a metal thin film type backing film provided on the other surface side of the support. A magnetic recording medium comprising a coat film and a film of a fluorine-based lubricant provided on the back coat film.